The present invention relates to device controllers and operating methods therefor and more particularly conveying systems employing such controllers locally.
There is described in U.S. Pat. No. 4,696,386, a diverter turn assembly that can be configured to divert articles from a path of a conveying system to another path, to merge articles arriving on two paths into one path or to function as a corner section. Such a turn assembly includes an array of wheels or rollers mounted on a frame. The wheels or rollers are arranged so continuously moving belt(s) on which the articles travel pass freely through the array. The wheels or rollers of the turn assembly are normally disposed beneath the surface of the belts and raised pneumatically when required to change the direction of the moving product or article. The rollers for the corner sections are typically arranged so they always present a contact surface slightly higher than the belts. The orientation and shape of the wheels is adjusted to match the function to be formed (e.g., diversion, merger, turning at a corner). For example, for a merge unit the rollers are orientated across the belt line.
Although such a device can readily divert and turn articles, it is limited to a single change in direction for diversion or merging (i.e., xe2x80x9cTxe2x80x9d conveying system configurations). This increases the size and number of sections required to divert and/or merge articles. Although this device also is well suited for diverting and merging articles in conveying system, it has limited capability to sort articles in particular when performing high speed sorting operations.
The universal controller for this device, as described in co-pending U.S. application Ser. No. 08/752,587 now U.S. Pat. No. 5,984,498, is well suited to control the performance of the diverting and merging functions by the device. However, it also has limited capability to perform sorting operations, in particular high speed sorting operations. As also described therein, this controller uses a local area communication scheme to control the operation of systems or devices connected to the controllers and thereby decentralize these control functions.
Additionally, other existing control systems and control methodologies, particularly those for conveying systems, employ some form of centralized control over multiple device controllers. For example, two device controllers are hard wired inter-connected to a programmable logic controller (PLC) or a plurality of PLCs, each being hardwired to device controllers, are hard wired connected to another central PLC. To effect a change in the operation of one device in response to changing conditions for another device, the PLC identifies the changing conditions and sends a signal to the other controller.
Such other systems are difficult to modify in the field by the user (i.e, not user friendly). System modifications typically involves re-configuring or replacing each control component (i.e, controller and PLC) in the system. As such, these types of systems are expensive and time consuming and have little flexibility for field modification.
Conveying and sorting systems traditionally have been custom designed with centralized controls and complex customized software for tracking articles or goods in movement in the system. Modifications to such systems entail adjustments to the centralized controls, revision to the customized software and the de-bugging required following such changes to assure proper system operation. Further, because the software and controls for each system is customized for each system, it is difficult to combine the control logic with the mechanical of the conveying system.
As such, there is a need for an apparatus that is configurable to selectively and automatically perform uni-directional and/or bi-directional sorting and diverting of articles. More particularly an apparatus that can perform high speed uni-directional and/or bi-directional diversion and sorting. There also is a need for such a controller to communicate with each other on a local area basis. Additionally, there is a need for a controller which is particularly configured to support the high speed sorting and/or diverting capability of the sorting/diverting apparatus. Such controllers also should not require hard wired interconnections but use communication protocols and equipment as a means for communicating between controllers. There also is a need for a sorting system that uses one or a plurality of such apparatuses. There also is a need for a conveying system that uses such an apparatus in conjunction with other conveying sections using local area based communication schemes and controllers so as to increase flexibility while maintaining control over the flow of goods or articles through the system without centralized control and customized software. Moreover, there is a need for conveying and sorting systems that are modularized in design and operation so customized engineering is not required.
The present invention features an apparatus that is configurable to selectively and automatically perform uni-directional and/or bi-directional diverting of articles being transported on a plurality of moving belts. Such an apparatus can be used in conveying systems to divert articles being transported in up to two directions. The apparatus also is particularly suited for performing high speed uni-directional and/or bi-directional sorting of these articles. Also featured is a controller or device that controls one or more of such apparatuses and systems using such an apparatus and controller.
In specific embodiments, the sorting/diverting apparatus diverts articles that are being conveyed on a plurality of moving parallel moving belts at a preselected nominal base height. The preselected nominal base height also corresponds to the top of the moving belt. The apparatus includes a plurality of diverting shafts, a shaft support frame, a frame moving mechanism, a drive motor and a drive mechanism.
The plurality of diverting shafts each have a long axis and are rotatably mounted to the shaft support frame. In a particular embodiment each diverting shaft is a hollow aluminum tube with a urethane coating to improve gripability. Each diverting shaft is substantially parallel to the plurality if moving belts. In particular embodiments, the number of diverting shafts is one more than the number of moving belts and includes a pulley, or a toothed pulley, mounted at one end thereof.
The drive mechanism interconnects each of the diverting shafts to the drive motor so that rotation of the drive motor causes each of the diverting shafts to rotate in a predetermined direction and speed. In a particular embodiment, the drive motor and drive mechanism cooperate so the plurality of diverting shafts are selectively and simultaneously rotated in either a clockwise or counterclockwise direction. More particularly, the drive motor is a reversible electrical motor, e.g., a reversible DC electrical motor, that causes the diverting shafts to rotate in the clockwise and counterclockwise directions.
In a more specific aspect of the instant invention, the drive motor includes a drive pulley, preferably a toothed drive pulley being interconnected to the motor drive shaft. The drive mechanism includes a drive belt, e.g. a continuous drive belt, and at least one idler wheel or idler pulley that is mounted to the shaft support frame. The drive belt is passed or wound about each of the diverting shaft pulleys, the drive pulley and each of the idler pulleys in a serpentine fashion. In this way, rotation of the drive pulley results in the simultaneous rotation of the diverting shafts. The at least one, preferably two, idler pulleys maintain tension in the drive belt as the support frame is being moved back and forth between first and second positions as hereinafter described.
The frame moving mechanism selectively moves the shaft support frame back and forth between the first and second position. In the first position, the frame moving mechanism arranges the support frame so the top of each diverting shaft is disposed below the preselected base height, i.e., is below the top surface of the moving belt. In the second position, a portion of each diverting shaft is disposed above the preselected base height to raise an article that was traveling along the plurality of moving belts so the article is no longer in contact with, and thus not moving along, the moving belts.
The shaft support frame further includes two end plates, on which each of the plurality of diverting shafts is rotatably secured thereto. Each plate includes two through apertures in the opposing surfaces of the two end plates. These through apertures are oval in configuration with the major axis of the aperture being parallel to the plane in which the plurality of moving belts lie. The through apertures in one end plate are aligned with the through apertures in the other plate.
The frame moving mechanism includes a plurality of stepping shafts, a second drive motor, and a second drive mechanism. The second drive mechanism interconnects each of the stepping shafts to the second drive motor so that rotation of that motor causes each of the stepping shafts to rotate about 180xc2x0 in a predetermined direction. The second drive motor and second drive mechanism also cooperate so the plurality of stepping shafts are selectively and simultaneously rotated in either a clockwise or counterclockwise direction.
Each stepping shaft includes a pin extending outwardly from each end of each shaft (i.e., two pins per shaft). In this way, the long axis of the pin is essentially parallel to the long axis of the shaft. Additionally, the pins are eccentrically mounted to each end at corresponding tangential positions. Each stepping shaft is disposed between the two end plates so the pins at either end of the shaft are disposed in one of the apertures in each of the two end plates and slidably engage the interior surface of the through aperture.
When the second drive motor rotates in one direction, the pins rotate in a generally upwardly direction. Because the pins slidably engage the interior surfaces of the through apertures, this rotation causes the end plates, and correspondingly the diverting rollers secured thereto to move upwardly. In this way, at least a portion of the rollers are disposed above the drive belts. However, when the second drive motor is rotated in another direction (e.g., clockwise), the pins are rotated in a generally downwardly direction. This downward motion causes the end plates as well as the diverting rollers to move downwardly so the rollers are disposed below the surface of the moving belts. Thus, the diverting rollers and the associated support frame are thereby selectively moved back and forth between the first and second positions.
In more particular embodiments, the second drive mechanism includes a drive pulley or sprocket for the second drive motor, a pulley or sprocket for each stepping shaft and a chain. The drive motor sprocket rotates responsive to the rotation of the motor. Each stepping shaft sprocket is mounted about a stepping shaft so rotation of the sprocket causes the stepping shaft to rotate. The chain is wound or passed about the drive motor sprocket and the stepping shaft sprockets so the rotation of the drive motor causes the stepping shafts to rotate in the same direction simultaneously and at a predetermined speed.
The drive motor is a quarter turn air operated rotary actuator under the control of a four way air valve. The air valve controls the air being admitted to the air actuator so it is selectively rotated in either a clockwise or counterclockwise direction. In an exemplary embodiment, the rotary actuator includes a vane on either side of which are ports for admission of pressurized air and for venting air. Rotation of the vane in either the clockwise and counterclockwise direction is accomplished by the appropriate admission of pressurized air to one side of the vane and venting pressurized air from the other side.
In another aspect of the instant invention, the sorting/diverting apparatus further includes a control device that selectively controls the operation of the frame moving mechanism and correspondingly the movement of the frame between and among the first and second positions. More particularly, the control device provides outputs to control the operation of second drive motor to move the support frame between the first and second positions. In a specific embodiment, the control device controls the operation of the four-way air valve and thereby the admission of and the venting of pressurized air to/from the air operated rotary actuator.
In a second aspect of the instant invention, the control device controls the operation of the diverting shaft drive motor and associated drive mechanism. More specifically, the drive motor is controlled so each of the diverting shafts is rotated in a predetermined direction at least when the portion of the diverting shaft is disposed above the nominal base height. When the sorting/diverting apparatus of the instant is configured to perform bi-directional diversion or sorting, the control device controls the operation of the diverting shaft drive motor so the diverting shafts are selectively rotated in a clockwise or counterclockwise direction.
In a third aspect of the instant invention, the control device is a novel apparatus controller that includes at least one, or at least two, bi-directional inflow and outflow communications ports, a processor and an applications program for execution with the processor. The processor processes information and provides outputs, where at least one output controls the device. The applications program includes instructions and criteria for processing the information and providing processor outputs. Specifically, the applications program includes instructions and criteria for communicating information between and among controllers; instructions and criteria for processing information received by a controller; instructions and criteria for modifying the operation of an apparatus responsive to the communicated information; instructions and criteria for modifying the operation of an apparatus responsive to status information relevant to apparatus operation; and for providing outputs for visual status displays and warning devices. In a preferred embodiment, such an apparatus controller is configured so one controller separately controls the operation of two sorting/diverting apparatuses as hereinabove described.
The apparatus controller further includes a read/write memory for storing data and parameters that control the operation of the applications program. The applications program also further includes instructions and criteria for controlling data storage in the read/write memory as well as instructions and criteria for real time tracking of data related to operation of the apparatus and system performance.
To communicate information between and among the controllers of the system, a communications link is established between each pair of controllers. This link is established by electrically interconnecting one bi-directional outflow port of one controller to one bi-directional inflow port of another controller.
The controller of the instant invention may be programmed or re-programmed by means of the RS232 I/O port or by means of the communications network established by the electrically interconnected controllers. To effect programming/re-programming of a controller via the communications links, the applications program further includes instructions and criteria for reprogramming the processor/controller responsive to instructions and information communicated through a bi-directional inflow port.
In a fourth aspect of the instant invention, the apparatus controller receives an input from a tick signal generator that provides a periodic output signal representative of the motion of the drive belt over a unit of time. The periodic signals from the tick generator are used by the applications program to control the operation of the apparatus. For example, the signals are used to update the position of the article in the data table which in turn is used to determine when to raise the diverting shafts to divert the article in the appropriate direction. When there are a plurality of such controllers in a conveying or sorting system, the periodic tick signals from the tick generator are communicated from the controller receiving the periodic signal input to the other apparatus controllers of the system.
In a fifth aspect, the instant invention includes a sorting system including at least one sorting/diverting apparatus, at least one apparatus controller and at least one tick signal generator all as hereinabove described. When the system includes a plurality of sorting/diverting apparatuses, there is at least one apparatus controller for each sorting/diverting apparatus and preferably there is one apparatus controller for each pair of sorting/diverting apparatuses.
Such a system also includes at least one display for each direction of sortation or diversion provided. Each of the displays includes a alphanumeric readout to display status information, e.g., the number of items that have been being diverted or sorted. The display further includes a warning device, such as signal lamp, which provides an indication of the satisfaction of some preset condition. For example, an indication that a preset number of items have been sorted into a box. The apparatus controller would also be typically configured to stop sending any further items to this box because it would be considered full.
The display also includes at least one and preferably two buttons or switches for purposes of resetting certain apparatus controller functions. As indicated one function of the sorting/diverting apparatus could be to fill a box. These buttons or switches provide the mechanism by which a user can reset the controller and related counters to continue sorting/diverting after the user has resolved or eliminated the warning condition. For example, put an empty box in place of the full box.
The system further includes at least one sensing mechanism, such as a photo eye to detect the presence of an article, e.g., box, entering onto a section including at least one sorting/diverting apparatus of the instant invention. The sensing mechanism is used to locate the article at a predefined position for purposes of tracking the article as it passes through the section. Such sensing mechanisms also can be used to provide a positive indication that an article was properly diverted. As such, an apparatus controller according to the instant invention has the capability of receiving inputs from each of these sensing mechanisms, e.g., includes five inputs.
In a sixth aspect, the instant invention includes a conveying system that utilizes a multiplicity of different section types to transport articles in a controlled manner. For example, the conveying system of the instant invention may include straight sections, accumulation sections, spacer sections, index sections, alternative conveying system diverter sections and merge sections. For details regarding these conveying system sections and the associated section controller, reference shall be made to U.S. patent application Ser. No. 08/752,587, the teachings of which are incorporated herein by reference. In a more specific embodiment, such a conveying system includes at least one high speed sorting/diverting apparatus of the instant invention. Each of these conveying system sections include a controller for that section.
For the straight sections, accumulation sections, spacer sections, index sections, alternative conveying system diverter sections and merge sections, hereinafter conveying system sections, the applications program in each conveying section controller, preferably includes the instruction and criteria to control the operation of any of these different section types. The applications program accesses the control routines specific to the operation of a given type of conveying section (e.g., an index section) by evaluating the data and configuration parameters stored in the read/write memory. For example, the section type is a parameter that is stored in a data table set up in the read/write memory. The applications program for the sorting/diverting apparatus controller is as described above.
In operation, data relating to the articles on the various sections making up the conveying system is stored in the read/write memory for a given controller. The applications program also further includes instructions and criteria for real time tracking of articles on each conveying section. Thus, a remotely located host computer, using the communications network established between and among the controllers, can make an inquiry to any controller for such real time information. Further, when articles are transferred from an upstream conveying section to a downstream section, the data stored in the read/write memory of the upstream controller is communicated to the downstream controller.
As described above, local displays are provided for each sorting/diverting apparatus controllers, where the number of displays being provided is a function of the number of apparatuses being controlled by the apparatus controller and whether the apparatus is uni-directional or bi-=directional. For example, four displays are provided for a controller which is controlling two bi-directional sorting/diverting apparatuses.